Distributed network services may be provided by servers situated in distinct zones, such that client devices accessing the service are supported by servers in a zone designated for the client device. However, static zone designations can lead to imbalance. Some zones may become over-subscribed or may support high-demand clients. This can result in poor service for clients within an over-subscribed or heavily loaded zone. Furthermore, other zones may have unused capacity and/or clients with lower support requirements than the high-demand clients. The resources in such zones are under-utilized and effectively wasted.